Back to EveryPatent.com



United States Patent 5,590,699
Gilbert ,   et al. January 7, 1997
Mechanism for rotating a tree-felling implement and tree-felling implement therewith

Abstract

The mechanism is used for rotating a tree-felling implement rotatably connected to a distal end of a boom of a logging vehicle by an implement pivot. The mechanism comprises a first arc-shaped member that extends in a plane perpendicular to the boom plane and is convex with reference to the implement pivot. The first member has a first end rotatably connected to the frame of the implement at a given distance from the implement pivot. A second arc-shaped member, coplanar with the first member, is also convex with reference to the implement pivot. The second member has a first end rotatably connected to the second end of the first member for defining an intermediary junction, and a second end rotatably connected to the distal end of the boom. A hydraulic actuator is mounted on the frame of the implement and has an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator. The mechanism provides a simple and reliable construction for rotating a tree-felling implement that is capable of rotating the implement with reference to the boom plane in both directions and according to a wide range of angles.

Inventors: Gilbert; Sylvain (1641 boul. St-Dominique, Roberval, Quebec, CA); Taillon; Michel (St-Felicien, CA)
Assignee: Gilbert; Sylvain (CA)
Appl. No.: 571076
Filed: December 12, 1995

Current U.S. Class: 144/34.1; 144/4.1; 144/336; 414/680; 414/694; 414/695.5; 414/739
Intern'l Class: A01G 023/08; E02F 003/32
Field of Search: 144/4.1,24.13,34.1,34.5,335,336,338 30/379.5 414/680,694,695,695.5,695.7,722,729,739

References Cited
U.S. Patent Documents
2681739Jun., 1954Gokey.
3027026Mar., 1962Couquet.
3081891Mar., 1963Przybylski.
3197049Jul., 1965Schwing.
3217910Nov., 1965Waite.
3278046Oct., 1966Shumaker.
3495727Feb., 1970Long.
3498350Mar., 1970Maradyn144/34.
3550794Dec., 1970Suverkrop.
3796331Mar., 1974Dutton.
3840132Oct., 1974Howells, Jr. et al.
4134505Jan., 1979Watanabe.
4412777Nov., 1983Forslund144/34.
5074740Dec., 1991Weigel414/550.
5109900May., 1992Gilbert144/34.
5291926Mar., 1994Jansson144/34.

Primary Examiner: Bray; W. Donald
Attorney, Agent or Firm: Merchant, Gould, Smith, Edell Welter & Schmidt
Parent Case Text


RELATED APPLICATION

The present patent application is a continuation-in-part of U.S. patent application Ser. No. 08/419,713 filed on 10 Apr. 1995, still pending.
Claims


What is claimed is:

1. A mechanism for rotating a tree-felling implement, the tree-felling implement comprising a frame rotatably connectable to a distal end of a boom of a logging vehicle by an implement pivot, the boom generally defining a boom plane, the mechanism comprising:

a first arc-shaped member extending substantially in a plane perpendicular to the boom plane and being convex with reference to the implement pivot, the first member having a first end rotatably connected to the frame of the implement at a given distance from the implement pivot;

a second arc-shaped member substantially coplanar with the first member and being convex with reference to the implement pivot, the second member having a first end rotatably connected to the second end of the first member and thereby defining an intermediary junction, and a second end rotatably connected to the distal end of the boom; and

an actuator mounted on the frame of the implement, the actuator having an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator.

2. A mechanism according to claim 1, wherein the actuator is hydraulic.

3. A tree-felling implement comprising:

a frame;

a connecting means for rotatably connecting the frame at a distal end of a boom of a logging vehicle, the boom generally defining a boom plane and the implement being rotatable around an implement pivot;

a first arc-shaped member extending substantially in a plane perpendicular to the boom plane and being convex with reference to the implement pivot, the first member having a first end rotatably connected to the frame of the implement at a given distance from the implement pivot;

a second arc-shaped member substantially coplanar with the first member and being convex with reference to the implement pivot, the second member having a first end rotatably connected to the second end of the first member and thereby defining an intermediary junction; and a second end rotatably connected to the distal end of the boom; and

an actuator mounted on the frame of the implement, the actuator having an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator.

4. A mechanism according to claim 3, wherein the actuator is hydraulic.
Description


FIELD OF THE INVENTION

The present invention relates to a mechanism for rotating a tree-felling implement rotatably mounted at the distal end of the boom of a logging vehicle. The mechanism, the tree-felling implement, the boom and the logging vehicle form a tree-felling machine controlled by an operator and is to be used on logging sites.

BACKGROUND OF THE INVENTION

Tree-felling machines are used in mechanized tree harvesting for cutting down trees instead of using a manual chain saw. Each machine comprises a logging vehicle with a boom at the end of which is provided a tree-felling implement. In use, to cut down an adjacent tree, the operator moves the implement towards the base of the tree. The implement then grabs a trunk with a set of hydraulically actuated arms and cuts the trunk at the base with a saw or a felling shear. The trunk is laid down on the ground or in a truck afterwards. Some implements can also remove branches from the trunk while still grabbing it, otherwise branches may be removed by another machine or a manual chain saw, or even not be removed at all.

Because the boom is generally moving only in the vertical plane, the implement has to be able to rotate with reference to the boom plane so that it may grab an inclined or curved tree, or a tree laying on the ground. In conventional tree-felling machines, the implement is rotated by means of a single oblique hydraulic actuator having one end operatively attached to the boom and another end operatively attached directly to the implement. With such embodiment, the implement may not be rotated around its pivot according to a wide range of angles and this alters greatly the flexibility of the machine. In some situations, the operator may have to move the machine around the tree until a suitable angle is found, which may not be always possible because of the usually soft soil and all the obstacles in a logging site. This therefore lowers productivity and adds unnecessary wear to the machine parts.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a simple and reliable mechanism for rotating a tree-felling implement, and a tree-felling implement with such mechanism. It is further an object of the present invention to provide a mechanism capable of rotating the implement with reference to the boom plane in both directions and according to a wide range of angles.

More particularly, the object of the present invention is to provide a mechanism for rotating a tree-felling implement, the tree-felling implement comprising a frame rotatably connectable to a distal end of a boom of a logging vehicle by an implement pivot, the boom generally defining a boom plane, the mechanism comprising:

a first arc-shaped member extending substantially in a plane perpendicular to the boom plane and being convex with reference to the implement pivot, the first member having a first end rotatably connected to the frame of the implement at a given distance from the implement pivot;

a second arc-shaped member substantially coplanar with the first member and being convex with reference to the implement pivot, the second member having a first end rotatably connected to the second end of the first member and thereby defining an intermediary junction, and a second end rotatably connected to the distal end of the boom; and

an actuator mounted on the frame of the implement, the actuator having an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator.

It is also an object of the present invention to provide a tree-felling implement comprising:

a frame;

a connecting means for rotatably connecting the frame at a distal end of a boom of a logging vehicle, the boom generally defining a boom plane and the implement being rotatable around an implement pivot;

a first arc-shaped member extending substantially in a plane perpendicular to the boom plane and being convex with reference to the implement pivot, the first member having a first end rotatably connected to the frame of the implement at a given distance from the implement pivot;

a second arc-shaped member substantially coplanar with the first member and being convex with reference to the implement pivot, the second member having a first end rotatably connected to the second end of the first member and thereby defining an intermediary junction; and a second end rotatably connected to the distal end of the boom; and

an actuator mounted on the frame of the implement, the actuator having an end rotatably connected to or adjacent to the intermediary junction for rotating the implement during operation of the actuator.

A non restrictive description of a preferred embodiment will now be given with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a logging vehicle with the tree-felling implement according to the present invention.

FIG. 2 is a rear view of the implement, showing the implement in a central position with reference to the boom axis.

FIG. 3 is an elevational view of the implement shown in FIG. 2, showing the implement in an example of a first extreme angular position.

FIG. 4 is an elevational view of the implement shown in FIG. 2, showing the implement in an example of a second extreme angular position.

DESCRIPTION OF A PREFERRED EMBODIMENT

Reference numerals

The description and the drawings use the following reference numerals:

10 tree-felling machine

12 logging vehicle

14 boom plane

20 boom

22 proximal boom member

24 distal boom member

26 boom hydraulic actuator

28 boom hydraulic actuator

30 boom hydraulic actuator

32 first lever

34 second lever

40 tree-felling implement

42 frame

44 trunk grabbing arms

49 protective casing (of circular saw)

50 implement pivot

52 linking element

54 first pivot (of the boom linking element)

56 second pivot (of the boom linking element)

60 actuator

62 actuator pivot

70 first arc-shaped member

72 second arc-shaped member

74 first connection

76 second connection

78 third connection

General description of the invention

As shown in FIG. 1, the tree-felling machine (10) comprises a self-propelled logging vehicle (12) adapted for use on logging sites and controlled by an operator sitting inside a cabin thereof. As apparent for a person skilled in the art, many other kinds of logging vehicles can be used instead of the one illustrated in FIG. 1.

An articulated boom (20) is operatively mounted on the vehicle (12). This boom (20) is known as a felling boom or a tree boom. Its purpose is to allow movement of a tree-felling implement (40) in the vertical plane. The implement (40) is rotatably connected at the distal end of the boom (20) by means of an implement pivot (50). The boom (20) is described in detail further in the text.

The tree-felling implement (40) is used for cutting down the trees instead of using a manual chain saw. In use, to cut down an adjacent tree, the operator moves the implement (40) towards the base of the tree. The implement (40) then grabs a trunk with a set of hydraulically actuated trunk grabbing arms (44) and cuts the trunk at the base with a circular saw (48). Alternatively, a felling shear (not shown) may be used. The trunk is laid down on the ground or in a truck afterwards. The implement (40) is described in detail further in the text.

Because the boom (20) is generally moving only in the vertical plane, hereinafter referred to as "the boom plane (14)", the implement (50) has to be able to rotate around the implement pivot (50) so that it may grab an inclined or curved tree, or a tree laying on the ground. The present invention provides a simple and reliable mechanism (60) capable of rotating the implement (40) with reference to the boom plane (14) in both directions, clockwise and counterclockwise, and according to a wide range of angles. Although the present invention allows the implement (40) to have a range of angles of 90.degree. and over, one may choose to restrict the range angle to a value under 45.degree. and use the actuating mechanism of the present invention for its other advantages. Uneven extreme angles with reference to the boom plane (14) are also possible if desired. The actuating mechanism is described in detail further in the text.

The boom

The boom (20) comprises a proximal boom member (22) and a distal boom member (24) operatively connected to each other. The proximal boom member (22) is operatively connected to the vehicle (12) and is rotated by means of a hydraulic actuator (26). The distal boom member (24) is rotated with reference to the proximal boom member (22) by means of a hydraulic actuator (28). Of course, specific construction details are known in the art of heavy machinery.

In addition to the movement in the vertical plane, the boom (20) may be articulated at this proximal end (not shown) for left and right rotations with reference to the vehicle (12). Alternatively, the vehicle (12) may be able to turn on itself, as it is the case for the one illustrated in FIG. 1.

The boom (20) comprises other elements that are described further in the text.

The tree-felling implement

The tree-felling implement (40) itself is a device known in the art. It comprises a main frame (42) on which is located a trunk grabbing means, such as the trunk grabbing arms (44) actuated by the hydraulic actuators (46). The implement further comprises a circular saw and a protective casing (49) therefor. Other tree cutting means, such as a felling shear (not shown) may be used instead of the saw.

The implement pivot (50) is a bearing supporting the weight of the implement (40) and of a tree when one is in the implement (40). It comprises the usual parts for such a bearing, as apparent for a person skilled in the art.

The linking element

The linking element (52) is used for rotatably connecting the implement (40) to the distal end of the distal boom member (24). According to a preferred embodiment, as shown in FIG. 1, the linking element (52) comprises a first pivot (54), for connecting the implement (40) to the boom (20). A second pivot (56) is provided, closer to the frame (42) than the first pivot (54) for rotatably connecting the implement (40) to an end of a first lever (32). The first lever (32) has an opposed end rotatably connected to a hydraulic actuator (30). The same end of the first lever (32) is also rotatably connected to an end of a second lever (34). The second lever (34) has an opposed end rotatably connected to the boom (20). With this arrangement, the linking element (52) is moved in the boom plane (14) whenever the hydraulic actuator (30) is operated, thereby also moving the implement (40) in the boom plane (14).

The actuating mechanism for rotating the implement

As best shown in FIGS. 2 and 3, the actuating mechanism comprises a first arc-shaped member (70) extending substantially in a plane perpendicular to the boom plane (14) and convex with reference to the implement pivot (50). The first member (70) has a first end (74) rotatably connected to the frame (42) at a given distance from the implement pivot (50).

A second arc-shaped member (72) also extends perpendicular to the boom plane (14) and is convex with reference to the implement pivot (50). The second member (72) has a first end rotatably connected to the second end of the first member (70) and thereby defines an intermediary junction (76). The second end (78) of the second member (78) is rotatably connected to the distal end (24) of the boom (20), preferably on the linking element (52).

In order to move the first (70) and the second members (72), an actuator (60), preferably hydraulic, is mounted on the frame (42) with a pivot (62). The actuator (60) has an end rotatably connected to the intermediary junction (76). Of course, it can also be connected to a location adjacent to the junction (76) on either the first (70) or the second member (72) to achieve the same result since they are connected together.

In use, the implement (40) is rotated with reference to the implement pivot (50) by retracting or extending the movable part of the actuator (60). FIGS. 3 and 4 illustrate the positions of the members (70,72) in examples of two extreme angles.

Scope of the present description

Although a preferred embodiment of the invention has been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention.

Top